The influence of confinement on the hydrodynamic characteristics of a cylindrical pillar within a microchannel

John O'Connor, Jeff Punch, Nicholas Jeffers, Jason Stafford

Research output: Chapter in Book/Report/Conference proceedingConference contributionpeer-review

Abstract

Microfluidic cooling technologies for future electronic and photonic microsystems require more efficient flow configurations to improve heat transfer without a hydrodynamic penalty. Although conventional microchannel heat sinks are effective at dissipating large heat fluxes, their large pressure drops are a limiting design factor. There is some evidence in the literature that obstacles such as pillars placed in a microchannel can enhance downstream convective heat transfer with some increase in pressure drop. In this paper, measured head-loss coefficients are presented for a set of single microchannels of nominal hydraulic diameter 391μm and length 30mm, each containing a single, centrally-located cylindrical pillar covering a range of confinement ratios, b=0.1-0.7, over a Reynolds number range of 40-1900. The increase in head-loss due to the addition of the pillar ranged from 143%to 479%, compared to an open channel. To isolate the influence of the pillar, the head-loss contribution of the open channel was extracted from the data for each pillar configuration. The data was curve-fitted to a decaying power-law relationship. High coefficients of determination were recorded with low root mean squared errors, indicating good fits to the data. The data set was surface-fitted with a power law relationship using the Reynolds number based on the cylinder diameter. This was found to collapse the data well below a Reynolds number of 425 to an accuracy of ± 20%. Beyond this Reynolds number an inflection point was observed, indicating a change in flow regime similar to that of a cylinder in free flow. This paper gives an insight into the hydrodynamic behavior of a microchannel containing cylindrical pillars in a laminar flow regime, and provides a practical tool for determining the head-loss of a configuration that has been demonstrated to improve downstream heat transfer in microchannels.

Original languageEnglish
Title of host publicationASME 2015 13th International Conference on Nanochannels, Microchannels, and Minichannels, ICNMM 2015, collocated with the ASME 2015 International Technical Conference and Exhibition on Packaging and Integration of Electronic and Photonic Microsystems
PublisherAmerican Society of Mechanical Engineers
ISBN (Electronic)9780791856871
DOIs
Publication statusPublished - 2015
EventASME 2015 13th International Conference on Nanochannels, Microchannels, and Minichannels, ICNMM 2015, collocated with the ASME 2015 International Technical Conference and Exhibition on Packaging and Integration of Electronic and Photonic Microsystems - San Francisco, United States
Duration: 6 Jul 20159 Jul 2015

Publication series

NameASME 2015 13th International Conference on Nanochannels, Microchannels, and Minichannels, ICNMM 2015, collocated with the ASME 2015 International Technical Conference and Exhibition on Packaging and Integration of Electronic and Photonic Microsystems

Conference

ConferenceASME 2015 13th International Conference on Nanochannels, Microchannels, and Minichannels, ICNMM 2015, collocated with the ASME 2015 International Technical Conference and Exhibition on Packaging and Integration of Electronic and Photonic Microsystems
Country/TerritoryUnited States
CitySan Francisco
Period6/07/159/07/15

Keywords

  • Confinement ratio
  • Cylinder
  • Head-loss
  • Microchannels
  • Microfluidics
  • Pillar

Fingerprint

Dive into the research topics of 'The influence of confinement on the hydrodynamic characteristics of a cylindrical pillar within a microchannel'. Together they form a unique fingerprint.

Cite this